Update Profile

The user-editable profile, as PATCH /v1/users/me accepts it.

extra="forbid" fails the WHOLE save on an unknown key, not just that key — so the onboarding modal asking three questions against a one-field schema 422'd every non-empty submit and lost the organization with it. The two onboarding answers are first-class here now. Keep in step with account_store.PROFILE_FIELDS, which is what actually persists them.